Megachile exilis Cresson, 1872:265, ♂. 4 ♂♂, Texas (leg. Belfrage); Mitchell, 1937Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic Region. Part VIII. Taxonomy of the subgenus Chelostomoides, Addenda and Index (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 63 (4):381-421.:393, Type ♂ (A.N.S.P., No. 2349). - Fox, 1893Fox, W.J. 1893. Report on some mexican Hymenoptera, principally from lower California. Proceedings of the California Academy of Sciences ser.2 (4):1-25. (distribution); Cockerell, 1899Cockerell, T.D.A. 1899. Catálogo de las Abejas de Mexico. Biblioteca Agricola de las Secretaria de Fomento, Mexico, 1-20. (distribution); Cockerell, 1900Cockerell, T.D.A. 1900. The New Mexico bees of the genus Megachile and a new Andrena. The Annals and Magazine of Natural History ser. 7: v. 6:7-20. (distribution); Cockerell, 1901Cockerell, T.D.A. 1901. Flower and insect records from New Mexico. Entomological News 12 (2):38-43. (distribution); Cockerell, 1903Cockerell, T.D.A. 1903. A catalogue of the bees of California. Psyche 10:74-78. (distribution); Cockerell, 1906Cockerell, T.D.A. 1906. The bees of New Mexico. Transactions of the American Entomological Society 32:289-314. (distribution); Cockerell, 1914Cockerell, T.D.A. 1914. Descriptions and records of bees. - LVIII. The Annals and Magazine of Natural History ser. 8: v. 13 (76):424-433. (distribution); Mitchell, 1937Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic Region. Part VIII. Taxonomy of the subgenus Chelostomoides, Addenda and Index (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 63 (4):381-421. (distribution); Ruíz-Cancino & Coronado-Blanco, 2002Ruíz-Cancino, E. & J.M. Coronado-Blanco 2002. Artrópodos terrestres de los estados de Tamaulipas y Nuevo León, México. Serie Publicaciones Cientificas No. 4:1-376. (distribution); Owens et al., 2018Owens, B.E., L. Allain, E.C. van Gorder, J.L. Bossart & C.E. Carlton 2018. The bees (Hymenoptera: Apoidea) of Louisiana: An updated, annotated checklist. Proceedings of the Entomological Society of Washington 120 (2):272-307. (distribution); Esperanza de Pedro, 2021Esperanza de Pedro, D. 2021. . :. (distribution); Nava-Bolaños & Osorio-Olvera, 2022Nava-Bolaños, A. & L. Osorio-Olvera 2022. Estado del arte del conocimiento de biodiversidad de los polinizadores de México. Revista Mexicana de Biodiversidad 93:1-77. (distribution). - As Chalicodoma exilis: - Ayala, 1988Ayala, R. 1988. Abejas silvestres (Hymenoptera: Apoidea) de Chamela, Jalisco, México. Folia Entomológica Mexicana 77:395-493. (distribution); Snelling, 1990Snelling, R.R. 1990. A review of the native North American bees of the genus Chalicodoma (Hymenoptera: Megachilidae). Contributions in Science, Natural History Museum Los Angeles County 421:1-39. (distribution). - As Chalicodoma exilis exilis: - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209. (distribution).
Megachile studiosa Cresson, 1872:269, ♀. 3 ♀♀, Texas (leg. Belfrage). - Mitchell, 1937Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic Region. Part VIII. Taxonomy of the subgenus Chelostomoides, Addenda and Index (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 63 (4):381-421.:391 ( listed as synonym of Megachile exilis Cresson, 1872); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209.:2074 ( listed as synonym of Chalicodoma exilis exilis (Cresson, 1872)); Snelling, 1990Snelling, R.R. 1990. A review of the native North American bees of the genus Chalicodoma (Hymenoptera: Megachilidae). Contributions in Science, Natural History Museum Los Angeles County 421:1-39.:19 ( listed as synonym of Chalicodoma exilis (Cresson, 1872)).
Megachile exilis parexilis Mitchell, 1938:393, Mitchell, 1937Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic Region. Part VIII. Taxonomy of the subgenus Chelostomoides, Addenda and Index (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 63 (4):381-421.:393, Type ♂ (A.N.S.P., No. 4165). Synonymized with Chalicodoma exilis (Cresson, 1872) by Snelling, 1990Snelling, R.R. 1990. A review of the native North American bees of the genus Chalicodoma (Hymenoptera: Megachilidae). Contributions in Science, Natural History Museum Los Angeles County 421:1-39.:19. - Mitchell, 1937Mitchell, T.B. 1937. A revision of the genus Megachile in the Nearctic Region. Part VIII. Taxonomy of the subgenus Chelostomoides, Addenda and Index (Hymenoptera: Megachilidae). Transactions of the American Entomological Society 63 (4):381-421. (distribution); Michener, 1947Michener, C.D. 1947. Bees of a limited area in southern Mississippi (Hymenoptera; Apoidea). The American Midland Naturalist 38 (2):443-455. (distribution); Mitchell, 1962Mitchell, T.B. 1962. Bees of the Eastern United States. Volume II. Technical bulletin (North Carolina Agricultural Experiment Station) 152:1-557. (distribution); Hall & Ascher, 2011Hall, H.G., & J.S. Ascher 2011. Surveys of wild bees (Hymenoptera: Apoidea: Anthophila) in organic farms of Alachua County in north-central Florida. The Florida Entomologist 94 (3):539-552. (distribution). - As Chalicodoma exilis parexilis: - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 2. Apocrita (Aculeata). Smithsonian Institution Press, Washington D.C. 1199-2209. (distribution). - As Megachile parexilis: